Get into a mistaken marriage where a women dumps you and tries to take it all and get reamed by the family law courts and your mythical "i dont need protection" would get washed away. I've seen men destroyed by divorce that was not of their own making. Your swagger is foolish in the extreme.
Maybe the "defense of marriage" act we need is one which raises the bar on divorce. Easy divorce has harmed more families then any other cause. Divorce is what has weakened marriage in this country, not homosexuality, incest, or bestiality.
But nobody wants to deal with the divorce problem. All this ranting about gay marriage weakening the institution reminds me of the story of the drunk looking for his lost keys under the streetlight. Someone comes along and offers to help, asking "where did you lose them?" "In the alley," the drunk replies, "but it's too dark to see anything there."
Like the drunk, so-called "defenders of marriage" are not addressing the hard problem, but are searching for a solution in a place that won't do them any good.